science

SCANFAR

SCANFAR is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand SCANFAR rather than just read about it. In short: The Hughes SCANFAR was the first phased array radar system to be deployed by the US Navy, installed on USS Long Beach (CGN-9) and USS Enterprise (CVN-65). It consisted of two search radars, the AN/SPS-32 and the AN/SPS-33.

Key takeaways

SCANFAR belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect SCANFAR to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of SCANFAR from memory before moving on to harder problems.

Reference excerpt

The Hughes SCANFAR was the first phased array radar system to be deployed by the US Navy, installed on USS Long Beach (CGN-9) and USS Enterprise (CVN-65). It consisted of two search radars, the AN/SPS-32 and the AN/SPS-33. In 1982, the system was removed from Long Beach, and was replaced by the AN/SPS-48 during a comprehensive overhaul. Aboard the Long Beach, the system used AN/SPG-55 radars for missile guidance. Despite its failure to enter widespread service, the lessons learned were applied to the follow-on Aegis Combat System and the associated AN/SPY-1 passive electronically scanned array (PESA) radar.

History Prior to the development of SCANFAR, the Navy had been developing an advanced anti-aircraft weapon system combining an extremely advanced radar system, the AN/SPG-59, with a new long-range missile known as the RIM-50 Typhon. The radar was an active electronically scanned array that acted both as a long-range surveillance system as well as the target illumination and guidance system for the missiles. The system proved to be beyond the state of the art, in particular it required a large number of individual broadcast elements that proved to be unreliable and expensive. SCANFAR was to some extent a simplified version of the SPG-59. The main radar would be used solely for surveillance, with target illumination being left to existing radar systems used with earlier missiles like the RIM-8 Talos or RIM-24 Tartar. During development it was found that attempting to use a single antenna for both search and tracking did not work effectively, so the system was modified to use two antennas, one for surveillance and another for tracking. Thus the system ended up using three radar antennas, and was, therefore, similar to earlier systems. An automatic tracking computer was added to the system in 1967. Also, in 1967, USS Long Beach detected and destroyed two North Vietnamese MiGs, utilizing the SCANFAR and Talos missile systems. In service, the system proved to be temperamental, due largely to the huge number of vacuum tubes it used. Despite this, the "air picture" it provided was good, with over-the-horizon capabilities. In 1967, during a shipyard overhaul period, the Long Beach radar system was converted from electronic tubes to solid state electronic boards. Converting to solid state for radar and radio equipment lightened the superstructure by 20 tons. AN/SPS-33 was an S band radar with a pencil beam function that could focus a single radar beam on a target. The pencil beam could be manually operated. SCANFAR was eventually replaced by the AN/SPS-48E.

AN/SPS-32 was a horizontally wide rectangular antenna for air surveillance. AN/SPS-33 was a vertical narrow rectangular antenna for target tracking. According to Navy documentation, the AN/SPS-33 was frequency-scanned in elevation and phase-scanned in azimuth.

Illustrations

Worked examples

Example 1 — a first encounter with SCANFAR

Start with the simplest possible case. Write down what SCANFAR claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to SCANFAR before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about SCANFAR ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of SCANFAR

In research: SCANFAR appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses SCANFAR in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: SCANFAR is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cold War military radars of the United States, Early warning radars of the United States Navy, Military electronics of the United States, so understanding it makes those chapters shorter.
In everyday life: Look for SCANFAR outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study SCANFAR in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what SCANFAR means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain SCANFAR out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is SCANFAR in simple terms?

Why does SCANFAR matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study SCANFAR?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on SCANFAR.